From your description I can be almost sure they are striped cucumber beetles. If you want something completely non toxic you can use yellow sticky traps. They are nothing more than plastic that is the partcular shade of yellow that attracts them best. That is covered with a sticky substance and works like fly paper. When the trap is loaded so that there is not enough exposed sticky left to catch them you wash it off apply more sticky and hang it to catch more. Cucumber beetles are very attracted to yellow. The drawback to this method is that you need a lot of sticky traps to be very effective but the advantage is that it is harmles. You will catch a few other insects but few of them will be predators. They are usually sold as a kit, containing plastic discs or squares and a tube of the sticky. You may need more of the sticky than comes in the kit but it can be bought seperately.
If you don't mind using an organic spray pyrethin has been found effective. Neem doesn't kill them but plants sprayed with it are less attractive to them. They don't like its odor or taste.
As with any broad spectrum insecticides try to restrict their use to the areas with the highest population of striped cucumber beetles and don't spray the entire garden. That would destroy your predators and allow all sorts of pests to run wild without natural controls.